Set in the 1830s and beginning on a slave plantation in Barbados, Esi Edugyan’s Washington Black tells the story of the eponymous Washington and his unlikely adventures as he meditates upon the complexities of race, relationships, science, and art. In 1830, Wash is an uneducated, orphaned slave boy around 10 or 11 years old taken under the wing of Big Kit, a powerful and intimidating field slave. Big Kit protects him from the other slaves and tries to ensure his safety. When new master Erasmus Wilde comes to the plantation, however, she realizes that no one will be safe from his escalating tactics of cruelty and brutality. She resolves to kill Wash and commit suicide, relying on her belief that, according to her religion, she will wake up free in her home country of Dahomey in Africa.

An uptick in slave suicides drives Erasmus to hold a demonstration in which he beheads a dead slave to prevent further suicides. Soon after, Erasmus summons Wash and Big Kit to his table, where they witness Erasmus and his brother argue over science and personal matters. Erasmus’ brother Christopher Wilde, also known as Titch, selects Wash to be Titch’s personal assistant in his scientific experiments, which separates Wash from Big Kit for good.

Wash assists Titch in conducting his experiments, including the assembly of a prototype of a flying machine that Titch dubs the Cloud-cutter. They erect the Cloud-cutter on the peak of a nearby mountain. Wash is injured and severely burned during a demonstration. During this time, Erasmus and Titch’s cousin Philip comes to stay with them. Philip is a melancholy and troubled young man, and Wash is uneasy around him. After several weeks, Philip tells Titch and Erasmus that their father, Mr. Wilde, has passed away after an accident in the Arctic. Titch and Erasmus are shocked and grief-stricken, but soon begin to make plans. While Erasmus insists that he must go to England to settle Mr. Wilde’s estates, Titch is reluctant to remain on the plantation, and a conflict between the two brothers ensues.

While out hunting with Erasmus and Philip, Titch expresses the desire to return to England and bring Wash with him. Erasmus counters that this isn’t possible, and that Erasmus has already promised Wash’s services as an illustrator to a visiting scientist who will be arriving on the island shortly. Later that evening, Philip takes Wash out to an abandoned area beneath the mountain before Philip commits suicide. Fearful that someone may punish or kill Wash, Titch takes Wash and flees the island in the Cloud-cutter.

During their flight, a storm takes down the Cloud-cutter, and they crash into a ship heading for Virginia. Arriving in Virginia, Titch and Wash head to an acquaintance involved in the Underground Railroad, and Titch offers Wash the option of escaping as a free man to Canada. Wash refuses this option, instead preferring to remain with Titch as he heads to the Arctic, believing that Mr. Wilde might still be alive. In Virginia, Wash and Titch learn that Erasmus has sent a bounty hunter named John Willard after Wash, with instructions to retrieve Wash dead or alive. Wash and Titch sail to the Arctic, where Titch discovers that Mr. Wilde is in fact still alive. After Titch and Mr. Wilde reunite, they get into an argument that results in Titch fleeing the camp, and Titch is presumed dead. Mr. Wilde searches for Titch and then falls ill and passes away from exposure. Now on his own, Wash leaves the camp and heads for Canada to pursue his future.

In Nova Scotia, Wash meets the grim reality of life in a 19th century fishing town. Without any significant connections, he drifts from job to job. During this time, he experiences a renewed interest in science and art and begins to sketch and paint once again. One day, as he sketches by the seashore, he meets a young woman named Tanna Goff who is also sketching marine life. They strike up a friendship, and a growing attraction develops. Wash learns that Willard may be in the area still on Wash’s trail. When Wash returns to the beach the next day, Tanna is gone.

At work, Wash receives a package to deliver to the house of a Mr. G.M. Goff and thinks that Tanna might be married. When he delivers the package, however, he discovers that Mr. Goff is her father, an esteemed scientist whose books Wash pored over while he studied under Titch. Mr. Goff invites Wash out on a boating trip, and Wash agrees. Wash and Tanna’s relationship continues to develop, although Mr. Goff does not immediately approve. After an outing with the Goffs, Wash develops the idea for an aquarium with living aquatic specimens.

Willard appears and confronts Wash one evening while Wash is working on his plans for the aquarium. Now working in insurance, Willard is a broken man after years of bounty hunting and tells Wash that, while Erasmus is dead and the slaves of Faith Plantation have been freed, Titch may still be alive. Willard still harbors intense racial prejudice and attempts to assault Wash in the street. Wash stabs Willard in the eye and escapes, fleeing to Tanna’s house. Tanna tends to his wounds, and Tanna and Wash have sex. Tanna determines that Wash should travel to England with her and her father to escape Willard.

In England, Wash, Tanna, and Mr. Goff begin working on the aquarium project, named Ocean House. The fact that Titch might still be alive troubles Wash, and Wash goes to Titch’s mother looking for answers. While she has not seen Titch in several years and is not on good terms with her son, the manservant of the house refers Wash to a local abolitionist society for more information about Titch’s whereabouts. Around the same time, Wash and Tanna witness Willard’s hanging for the crime of murdering a freed black man.

At the abolitionist society house, Wash learns more about his own past, including his birth date and that Big Kit is actually his biological mother. The news that Big Kit passed away on the plantation before the slaves gained freedom unsettles and saddens Wash. He also learns that Titch is still alive, as Titch is the one who donated the papers to the archives regarding Faith Plantation. Wash writes several letters to a Peter Haas in Amsterdam, who he suspects might be the Peter House who worked with Mr. Wilde. Eventually, Wash and Tanna decide to travel to Amsterdam to put their suspicions to rest. At Peter’s house, Wash recognizes the old man as Mr. Wilde’s former assistant; Wash and Peter embrace and chat. Wash discovers that Titch has traveled to Morocco and now studies supernatural phenomena.

Wash and Tanna travel to Morocco, where they eventually find Titch working on a new prototype of the Cloud-cutter. Titch has also adopted another local boy to assist him in his scientific endeavors. Wash attempts to find closure with Titch, but is unable to make Titch see how abandoned Wash felt by Titch.